Major advances in anesthetic care over recent decades have led to a substantial reduction in intraoperative mortality. In contrast, longer term outcomes following surgery have remained less favorable, showing 30-day mortality rates upwards of 1-2% in the U.S. and even greater percentages worldwide. While intensive care unit care is being credited with having contributed to overall improved postoperative survival, the identification of those patients most likely to benefit from more intensive follow-up care (due to particularly increased risk beyond that of a higher ASA classification) has remained challenging.